The present invention relates to an absorbent structure including chemically treated and mercerized cellulose fibers for improved liquid distribution for use in disposable absorbent structures such as infant diapers, feminine hygiene pads and adult incontinence pads.
Absorbent products, such as infant diapers, feminine hygiene pads, adult incontinence pads, and the like, have traditionally utilized structures with various configurations and materials to provide the requisite absorbency performance. One objective in developing improved absorbent products has been to increase both the total absorbent capacity of the product, as well as the tenacity and reliability with which such products absorb and retain fluid loads. Another objective has been to provide thinner and more comfortable absorbent products.
To manage liquid body waste, the absorbent structure or structures within an absorbent product must generally be able to first uptake a liquid into the absorbent product, then distribute the liquid within the absorbent product, and finally retain the liquid within the absorbent product.
One way for improving the absorbency characteristics of an absorbent product has been to use entangled masses of fibers, e.g., non-woven fibrous webs, which can imbibe and retain liquids, such as discharged body fluids and other body exudates, both by absorption (e.g., fluid is taken up by the fiber material itself and retained in the capillary interstices between the fiber) and by wicking (e.g., fluid is distributed through diffusion and stored in the capillary interstices between fibers). Typically, however, structures of this type have had a limited storage capacity for fluids, a low rate of distributing fluids, and a limited ability to partition fluids from other materials.
Conventional fluff cellulose fibers and superabsorbent polymers are widely used for the absorbent core of absorbent products. Superabsorbent polymers (hereinafter xe2x80x9cSAPsxe2x80x9d) are capable of absorbing many times their own weight of liquid. SAPs have been used to increase the absorbency of absorbent products such as infant diapers, feminine hygiene pads and adult incontinence pads.
While an absorbent core of fiber and SAPs can provide improved storage characteristics, they can have shortcomings in transporting or distributing absorbed body fluids laterally from one region or zone to another. This can be troublesome in some products where body fluids are frequently discharged in periodic discrete gushes, and each gush of fluid discharged in this manner will generally encounter an absorbent structure with diminished capabilities to quickly and efficiently: (1) acquire subsequent gushes of fluid, (2) move fluid from the common discharge area to other unused, unsaturated, or relatively dry parts of the absorbent structure, (3) remain resistant to compression deflection, (4) recover from wet compression, and (5) partition fluids. Thus, the total absorbent capacity of the absorbent product is often not fully utilized.
It is an object of the present invention to provide an absorbent article able to exceed the wicking, partitioning or distribution characteristics of known absorbent structures.
Furthermore, it is an object of the present invention to have an absorbent structure that is capable of quickly distributing the liquid throughout the absorbent product.
The present invention is directed to an absorbent structure for use in a disposable absorbent product for absorbing bodily fluids. The absorbent structure includes a fluid storage layer including matrix fibers and a superabsorbent polymer for receiving fluids and a distribution strip positioned below said fluid storage layer. The distribution strip including cellulosic fibers and has a basis weight of between 45 grams per square meter and 140 grams per square meter and has a density of between 0.20 grams per cubic centimeter and 0.60 grams per cubic centimeter.